The field of the invention relates to providing relevant results in response to queries issued against large collections of information such as exist in large databases or on the Internet. The Internet is an extensive network of computer systems containing hundreds of millions of documents, files, data bases, text collections, audio clips, video clips and samples of any other type of information. Additionally, many companies have, and are growing, vast databases of information against which both internal and external queries are permitted, for instance, news archives. As used throughout, the term “information” will refer to data on a web page, the web page itself, attachments to a web page, data contained in a database or other storage device. Research engines and search techniques are available to users for use in locating information that they need. One search result ranking technique, identified as popularity ranking, is demonstrated in the patent entitled “Personalized Search Methods,” U.S. Pat. No. 6,182,068, which is incorporated by reference herein. A further description of the popularity ranking, is demonstrated in the patent entitled “Personalized Search Methods,” U.S. Pat. No. 6,006,222, which is also incorporated by reference herein. There are many other techniques utilized in an effort to reduce vast amounts of information down to a manageable amount, which fit the needs of users generally, or even a particular user. However, as more and more information gets added to databases or is made available over the Internet, continued efforts to refine and filter the information to satisfy the needs of users will be necessary.
Traditional techniques for ranking relevancy can become skewed over time. An example of this is use of the popularity technique of assigning relevancy, based on the absolute number of uses (“clicks”) the information has received. In the situation where the particular query of the “United States President” is entered, sites referring to Bill Clinton may have received numerous uses (hits) during his tenure as President, but the user in 2001 entering that query may be anticipating results for George W. Bush. Similarly, studies have shown that results that are ranked near the top of a result list generally receive more use than results further down on the list. Therefore, if relevancy ranking of results is based on number of uses, the ranking becomes somewhat self-fulfilling and the top results may never be displaced. Therefore, a technique that takes into account the age of uses, as well as other factors that would have led to higher or lower usage, is needed to refine relevant search results for users seeking information.